/**
 * TypeScript types for the Vela invoicing schema.
 * Keep these in sync with `invoicing-schema.sql`.
 */

// ── Enums ──────────────────────────────────────────────────────

export type InvoiceStatus = "draft" | "sent" | "paid" | "overdue" | "cancelled";

export const INVOICE_STATUS: Record<InvoiceStatus, InvoiceStatus> = {
  draft: "draft",
  sent: "sent",
  paid: "paid",
  overdue: "overdue",
  cancelled: "cancelled",
};

// ── Invoice ────────────────────────────────────────────────────

export interface Invoice {
  /** UUID — primary key */
  id: string;

  /** UUID — FK to organisations table */
  organisation_id: string;

  /** Auto-generated per org, e.g. "INV-0001" */
  invoice_number: string;

  /** Current lifecycle state */
  status: InvoiceStatus;

  /** ISO-4217 currency code, default "AUD" */
  currency: string;

  // ── Client (inline, no separate table for MVP) ──
  client_name: string;
  client_email: string | null;
  client_address: string | null;

  // ── Dates ──
  /** Defaults to CURRENT_DATE UTC on insert */
  issue_date: string; // ISO date string: "2026-04-06"
  due_date: string; // ISO date string: "2026-04-20"

  /** Legacy amount column in dollars (numeric). Kept for back-compat; new code should use total_cents */
  amount: number | null;

  // ── Amounts stored in cents (integer) to avoid floating-point issues ──
  subtotal_cents: number;
  tax_total_cents: number;
  total_cents: number;

  // ── Optional ──
  notes: string | null;

  // ── Metadata ──
  created_at: string; // ISO-8601
  updated_at: string; // ISO-8601
  /** Clerk user_id of the creator (nullable for legacy rows) */
  created_by: string | null;
}

// ── Invoice Line Item ──────────────────────────────────────────

export interface InvoiceLineItem {
  /** UUID — primary key */
  id: string;

  /** UUID — FK to invoices(id), CASCADE on delete */
  invoice_id: string;

  description: string;
  /** Decimal (12,2) — stored as string from Postgres; parse as needed */
  quantity: string;
  /** Stored in cents */
  unit_price_cents: number;
  /** Percentage, 0–100, with 2 decimal places (e.g. "10.00") */
  tax_rate: string;
  /** Computed & stored: quantity * unit_price_cents */
  line_total_cents: number;
  /** Display / sort order within the invoice */
  sort_order: number;
  created_at: string; // ISO-8601
}

// ── Derived / composite types ──────────────────────────────────

/** Invoice with its line items eagerly joined (for detail views) */
export interface InvoiceWithLineItems extends Invoice {
  line_items: InvoiceLineItem[];
}

/** Shape for creating a new invoice (client-side) */
export type CreateInvoiceInput = Omit<
  Invoice,
  "id" | "invoice_number" | "subtotal_cents" | "tax_total_cents" | "total_cents" | "created_at" | "updated_at"
>;

/** Shape for creating a new line item (client-side) */
export type CreateInvoiceLineItemInput = Omit<
  InvoiceLineItem,
  "id" | "line_total_cents" | "created_at"
>;

/** Shape for updating an existing invoice (partial) */
export type UpdateInvoiceInput = Partial<CreateInvoiceInput>;

/** Shape for updating an existing line item (partial) */
export type UpdateInvoiceLineItemInput = Partial<CreateInvoiceLineItemInput>;

// ── Helpers ────────────────────────────────────────────────────

/** Convert cents to a decimal string (e.g. 12500 → "125.00") */
export function centsToDecimal(cents: number): string {
  return (cents / 100).toFixed(2);
}

/** Convert a decimal amount to cents (e.g. "125.00" → 12500) */
export function decimalToCents(amount: string | number): number {
  const num = typeof amount === "string" ? parseFloat(amount) : amount;
  return Math.round(num * 100);
}

/** Compute line total in cents */
export function computeLineTotalCents(quantity: string | number, unitPriceCents: number): number {
  const qty = typeof quantity === "string" ? parseFloat(quantity) : quantity;
  return Math.round(qty * unitPriceCents);
}

/** Compute invoice subtotal and tax from line items */
export function computeInvoiceTotals(lineItems: { line_total_cents: number; tax_rate: string }[]) {
  let subtotal_cents = 0;
  let tax_total_cents = 0;

  for (const item of lineItems) {
    subtotal_cents += item.line_total_cents;
    const rate = parseFloat(item.tax_rate);
    tax_total_cents += Math.round((item.line_total_cents * rate) / 100);
  }

  return {
    subtotal_cents,
    tax_total_cents,
    total_cents: subtotal_cents + tax_total_cents,
  };
}

/** Human-readable invoice status labels */
export const INVOICE_STATUS_LABELS: Record<InvoiceStatus, string> = {
  draft: "Draft",
  sent: "Sent",
  paid: "Paid",
  overdue: "Overdue",
  cancelled: "Cancelled",
};